Power electronics devices are often utilized in high-power electrical applications, such as inverter systems for hybrid electric vehicles and electric vehicles. Such power electronics devices may be vertical current devices that include an electrode on an upper surface and an electrode on a lower surface of power semiconductor devices such as power insulated-gate bipolar transistors (IGBTs) and power transistors. The power semiconductor devices may be thermally bonded to a substrate and the substrate may then be further thermally bonded to a cooling structure, such as a heat sink.
With advances in battery technology and increases in electronics device packaging density, operating temperatures of power electronics devices have increased and are currently approaching 200° C. Accordingly, cooling of power electronics devices is desired. Also, traditional electronic device soldering techniques no longer provide suitable bonding of semiconductor devices to substrates and alternative bonding techniques are needed. One such alternative bonding technique is transient liquid phase (TLP) sintering. TLP sintering of semiconductor devices to substrates utilize bonding temperatures (also referred to as sintering temperatures) between about 280° C. to about 350° C. The semiconductor devices and substrates have different coefficients of thermal expansion (CTE) and large thermally-induced stresses (e.g., cooling stresses) may be generated between a semiconductor device and substrate upon cooling from a TLP sintering temperature. The large thermal cooling stresses due to CTE mismatch between the power semiconductor device and substrate may result in delamination between the semiconductor device and substrate of a power electronics device.